The prior art optically controlled oscillator assembly is described in U.S. Pat. No. 4,859,965, issued Aug. 22, 1989. The prior art optically controlled oscillator assembly includes a light source for emitting light at a wavelength in the region of 0.5 micrometers to 1 micrometer, control means coupled to said light source for controlling the intensity of the light emitted from said source, a fixed resistance, a GaAs multi-finger FET having parallel connected sources and parallel connected drains and parallel connected gate fingers, circuit means for connecting the sources and drains of said FET in series circuit with said fixed resistance across a source of positive dc voltage, optic fiber means optically coupled from said light source on the surface of said FET between the sources and drains of the FET and covering substantially all of the gate fingers of the FET, gate biasing means coupled to the gates of said FET for biasing said FET to a point near the pinch-off voltage to maximize the light sensitivity of the FET, a circuit junction of said fixed resistance and said FET, said circuit junction having an output lead, whereby changes in the intensity of light from said light source change the voltage drop across said FET and the voltage applied to said output lead.
One problem with the prior art optical control is that it is sometimes difficult to directly illuminate the surface of the single oscillator FET.
Examples of publications which described these types of devices include the following:
1. Paolella, A., P. R. Herczfeld, A. Madjar, and T. Higgins, "Optical response of the GaAs MESFET at Microwave Frequencies and Applications", 1991 MTT-S International Microwave Symposium Digest, pp. 487-490, June 1991, Boston, Mass.
2. de Salles, A. A. A., "Optical Control of GaAs MESFET's", IEEE Transactions on Microwave Theory and Techniques, Vol. MTT-31, No. 10, pp. 812-820, October 1983.
3. Sun, H. J., R. J. Gutmann, and J. M. Borrego, "Photoeffects in common-source and common-drain microwave GaAs MESFET Oscillators," Solid State Electronics, Vol. 24, No. 10, pp. 935-940, 1981.
Further U.S. patents and pending U.S. patent applications which describe other types of these devices include the following:
1. "Optical Control of a Microwave Switch", U.S. Pat. No. 5,073,718, issued Dec. 17, 1991 to Paolella; and
2. "Optical Control of a Microwave Switch" U.S. Pat. No. 5,073,717, issued Dec. 17, 1991 to Paolella et al.
3. "Optical Control of a Microwave Variable Attenuator", U.S. Ser. No. 07/788,630, filed Nov. 6, 1991. (Docket 4588.)